The broad long-term goals of the experiments described in this application are to determine if the environment an animal lives in can influence learning and memory abilities. To address these goals, we have outlined two specific aims. First, do unique elements of the environment that an organism lives in influence the ability to learn spatial relationships between cues and is working memory influenced by these experiences? Second, once learning has occurred, does the environment an animal lives in influence the long-term retention of these memories in the absence of continued practice? To evaluate these objectives, adult rats will be housed in a variety of conditions that have proven useful in systematically evaluating the effects of the environment on brain structure, function, and behavior. The independent variable will be the conditions an animal live in, such as social rearing, an opportunity to exercise, and living in an environment that changes frequently. Animals will be housed in their respective condition for a period of thirty-days prior to ten-days of behavioral testing. The dependent measure will assess both reference- and working-memory. Subsequently, subjects will be tested for the retention of these memories ten- or thirty-days later. Our preliminary data suggest that learning rates are not appreciably different between young animals housed socially and those living in environmentally complex conditions. However, when working memory is incrementally increased, subjects living in a more complex environment commit fewer errors, on average, than socially housed controls. Collecting multiple measures of brain function from the same subject will enhance our ability to draw inferences and offers to shed light on how such experiences might be expressed, and ultimately maintained in the mature nervous system. This research is useful in that it potentially offers additional insight as to how different experiences might contribute to both the learning and retention of memories in an enduring manner. By better understanding how such experiences influence brain function, we might be able to better refine strategies to promote healthy development and long-term maintenance of a healthy nervous system. [unreadable] [unreadable] [unreadable]